Packing for pistons



(No Model.)

F. M. LUDL0W.S1.

PACKING FOR PISTONS, PLUNGERS, &G.

No. 348,527. Patented Aug. 31, 1886.

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PACKING FOR PISTO PATENT OEEicE.

NS, PLUNGERS, 84.0.

SPECIFICATION forming part of Letters Patent No. 348,527, dated August 31, 1886.

Serial No. 184,702. (No model.)

To @ZZ whom, 2315 may concern.:

Be it known that I, Finnois M. LUDLow, Sr., of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in Packing for Pistons, 'Plun-y gers, &c., of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, and in which- Figurel is aside view of a piston-head with part of the pistonrod. Fig. 2 is a section at 2 2, Figs. l and Fig. 3 is a section at 3 8, Fig. 2. Fig. 4. is a perspective View of one of the blocks by which the packing-ring is made steanrtight at the ends of the sections. Fie. 5 is a section showing the packing` applied to a plunger, the section plane being transverse to the plunger. The same may be applied to a piston-rod.

A distinctive feature of this packing is that the packing-ring, or each section of the same,- is made of equal width from end to end, so that as it wears and its ends separate there is no opening made at the edges of the ring or section, as the case may be.

A is the piston-rod, and B the part of the piston-head which is secured to the pistourod by a key, O. D is the follower, held to the part B by bolts. rIlhcse parts need not be particularly described, as they may have the usual or any preferred construction.

Between the parts IE and Dis what is called the bull-ring E, having a diameter equal to the parts B and I). In the bull-ring is a circumferential groove, E', rectangular iu crosssection, in which the packing-ring sections F closely fit, the fit, however, not being so tight as to prevent the outward movement of the ring-sections as they wear away by friction against the cylinder. I have shown six of these sections; but they may be more or less in number. A single ring may be used with an opening at one place to allow expansion.

G are cylindrical blocks, having recesses equaling in cross-section the groove E', so that the ends of the ringsections shall fit snugly therein. The ends of the the ring-sections F extend to about the middle ofthe recess g, so that a lap-joint is made, preventing the passage of steam between the ends of the ringsections, as the ends of the ring-sections fit the cheeks g of the block. The blocks G fit snugly in cylindrical sockets II of the bulb ring, but with sufficient freedom to allow the blocks to move outward as the ring-sections wear away. The blocks G are pushed ontward by the springs I within recesses H', which form continuations of the sockets II.

At .I are shown steady-pins, which project from the bull-ring and occupy sockets in the ring-sections F, and whose purpose is to prevent eudwise movement in the ring-sections. The office of the springs is to carry the packing-ring sections outward as they wear away and keep them in contact with the engine` cylinder. The ends or cheeks gof the blocks G wear away equally with the section F by Afriction against the cylinder, so that there is no way for the passage of steam into the space between the ends of the sections F, as the space is enlarged by the wearing away of the sections by friction against the cylinder.

In Fig. 5 the packing is shown applied to a piston-rod or plunger, A. In this case the ring E is inserted in the cylinder or stuffingbox K, as the case may be. rIhc concave sides of the sections F bear against the piston-rod or plunger. They occupy the groove E and the recesses of the blocks Gv, and their ends are packed and forced inward by the blocks, the latter being pushed toward the pist-on rod or plunger A by the springs I.

Ii are screws,turning in screw-threaded holes of the stufting box or cylinder K, and bearing against the outer ends of the springs I.

I have spoken of the blocks G- and their sockets H as cylindrical, but I do not confine myself to this shape.

I am aware that it has been proposed to form a piston -head with a circumferential groove enlarged laterally at one point, and to iit in said groove a cut packing-ring, and in said enlarged portion a grooved block which embraces and overlaps the meeting ends of said ring, said block being forced radially outward by steam-pressure from the cylinder. This is not the equivalent of my invention, and I do not claim, per sc, any feature or features which my said invention may possess in common therewith. W'here steam-pressure is relied upon to expand the packing-ring the results are very unsatisfactory. For example, when the steam first enters the cylinder the ring will be in its normal or contracted IOO . cylinder.

condition; hence the steam may escape past the ring before the block has been forced outward, and said ring thereby brought to its bearing against the inner face of the cylinder. Furthermore, when the ring has come toits bearing there is nothing to regulate the force with which the block is pressed outward; hence the pressure of the packing-ring against the face of the piston will be proportional to the pressure per square inch of steam in the This is decidedly objectionable, as it causes unnecessary friction and Wear of the parts.

I am also aware that sectional overlapping packing-rings contained Within a peripheral groove in the piston-head'have been forced outward by spring-pressure; but this is not the equivalent of my invention, and I also disclaim any feature or features,pcr sawhich my said invention may possess in common there` with.

I claiml. The combination, with a piston-head having a circumferential groove, of the packing ring or sections occupying said groove, a radially-movable grooved block embracing and overlapping the contiguous ends of said ring or sections, a spring for forcing said block outwardly, and a socket inclosing the rear side of the block and preventing contact of steam therewith, as set forth.

2. The combination, with a piston-head having a circumferential groove, of the packing ring or sections occupying said groove, a radially-movable grooved block embracing and overlapping the contiguous ends of said ring or sections, having its rear side protected from the action of the steam admitted to the cylinder, and a spring for forcing said block outwardly, substantially as set forth.

3. The combination of the section F, steadypins J, fixed in the ring E and Working in the section, or vice versa, blocks G,and springs l,

all substantially as and for the purpose set forth.

4. The combination, with a piston having a circumferential groove and the ring or sections oecupying said groove, of the block embracing and overlapping the contiguous ends of said ring or sections, and a pin for preventing the movement of said ring or sections relative] y to said block, as set forth.

FRANCIS` M. LUDLOVV, SR.

In presence of- SAML. KNIGHT, BENJN. A. KNIGHT. 

